Kinetic parameters for imipramine N-glucuronide formation by UGT1A4 in single and double expression systems
Data are means ± S.D. of three independent determinations.
Clone | Km | Vmax | Vmax/Km |
|---|---|---|---|
| mM | pmol/min/unit | nl/min/unit | |
| 1A4 | 1.1 ± 0.1 | 91.7 ± 9.5 | 78.7 ± 4.6 |
| 49-1 | 1.1 ± 0.1 | 94.0 ± 5.2 | 85.9 ± 9.6 |
| 49-2 | 3.2 ± 1.3* | 314.9 ± 96.7* | 101.5 ± 11.4 |
| 49-3 | 4.0 ± 1.5* | 334.9 ± 105.4* | 85.4 ± 6.6 |
↵* P < 0.01 compared with the single expression system.